Astoria 2GR - Page 18

TECHNICIANS' manual
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2.9.9 CTS group
(withathermosiphoniccircuit)
In this system, the dispensing group (1) is heated by a ther-
mosiphonic circuit (2) connected to the heat exchanger (3).
The same water is used when dispensing coffee, thus ensur-
ing that all coffees are the same temperature:
• The solenoid valve and the pump are activated in order
to send cold water into the exchanger (3) through the in-
jector (4).
• The heating unit water is carried from the exchanger (3)
to the group (4) for dispensing.
• Thepumpallowsthewaterowpressure to increase to
8-9 bar for dispensing.
The injector (4)andtheowreducer(5) are important com-
ponents for the dispensing group’s operation. To increase the
coffeeextractiontemperature,removetheowreducer(5) or
replace it with one that has a bigger diameter. To decrease
the temperature, replace it with one that has a smaller di-
ameter. If necessary, the exchangers can be replaced by re-
moving the ange and disconnecting the relative hydraulic
circuit pipes. These operations should be carried out when the
machine has been switched off and has cooled down: always
replace the seals.
3
Water inlet
Dispensing
coee
5
34
DISPENSING IN PROGRESS
2
3
1
IDLE
2.9.10 Safety thermostat
The thermostat prevents any damage occurring to the elec-
trical heating element if there is no water in the heating unit.
The thermostat bulb (7) is located inside a sheath (8) in the
middle of the heating elements. The thermostat contacts (9)
are connected to the electric heating element (10). If the
electricheatingelementisexposedduetoafailuretollthe
heating unit with water, the temperature of the heating el-
ement increases dramatically. At this point, the thermostat
cuts the power supply to the heating element in order to pre-
vent damage occurring.
10
911
7
8
To reset the thermostat, press the centre button
(11). However, before starting the machine up
again, identify what prevented the water from
being fed into the heating unit.
2.9.11 Motor pump
This component feeds the machine
by increasing the water pressure to
0.8-0.9 MPa (8-9 bar) in order to dis-
pense coffee and automatically ll
the heating unit.
2.9.12 Electronic control unit
The electronic control unit is installed on the SAE versions.
Its purpose is to electronically control the cof-
fee dose via the water owing through the
dosing device and to check that the heating
unitisbeinglledwithwater.
Some versions of the control unit are set up
to be connected to the dispensing account-
ingsystemsbymeansofaspecicinterface
device.